This proposal outlines a research program consisting of a series of interrelated field experiments in classroom settings and laboratory experiments aimed at assesing the impact that interdependence has on attraction, performance, prejudice reduction, self-esteem and contentment. In the field experiments, children in classrooms will be divided into six-person groups, which will learn normal classroom material through the jigsaw process - a technique developed over the past few years in which each student has a part of the information necessary for the understanding of the lesson. This makes each child dependent on the other children. In past studies, we found that such interdependence changed the climate in the classroom. Children became less competitive, less hostile, more cooperative, liked each other more, liked themselves more, liked school more, and performed better - than children in traditional, more competitive classroom settings. We have also shown increases in empathic role-taking and in the perception of an internal locus of control. The present proposal extends this research by using the basic technique (with variations) in an attempt to investigate a variety of phenomena, including the processes whereby normal children relate to handicapped children - and in an attempt to reduce the incidence of teenage pregnancies. The program is considered to be important as basic research as well as applied research. It is aimed at increasing our understanding of the effects of cooperation versus competition as well as the development and evaluation of a viable and effective classroom innovation.